<!doctype html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <script src="https://unpkg.com/vue@3"></script>
    <title>Document</title>
  </head>
  <body>
    <div id="app">
      <ol>
        <li
          v-for="(item,index) in title"
          :key="index"
          @mouseenter="contentShow(index)"
        >
          {{item.item}}
        </li>
      </ol>
      <div class="box">{{showContent}}</div>
    </div>
  </body>
</html>
